Disclosed are intermediate transfer members, and more specifically, intermediate transfer members useful in transferring a developed image in an electrostatographic, for example xerographic, including digital, image on image, and the like, machines or apparatuses, and printers, inclusive of office and production printers. In embodiments, there are selected intermediate transfer members comprised of a phosphate ester and a polyimide, and more specifically the reaction product of a phosphate ester and a polyamic acid (polyimide precursor) to form a phosphate modified polyimide, each of the two components of the phosphate ester and the polyamic acid being commercially available. In embodiments thereof, the phosphate ester and the polyimide may be dispersed in or mixed with a suitable polymer, such as those illustrated herein, like a polyimide or a polycarbonate.
A number of advantages are associated with the intermediate transfer members, such as belts (ITB) of the present disclosure, like excellent acceptable resistivity, a high modulus, of for example equal to or greater than about 3,000 MPa, such as from about 3,000 to about 7,000 MPa, and where coating of the phosphate ester modified polyimide after being applied to a substrate, such as a metal substrate, possesses self release characteristics from the metal substrate; an excellent maintained member conductivity for extended time periods; ITB humidity insensitivity for extended time periods; wear and abrasion resistance; and acceptable surface friction characteristics for aiding in the transfer of developed xerographic images.
In a typical electrostatographic reproducing apparatus, a light image of an original to be duplicated is recorded in the form of an electrostatic latent image upon a photosensitive member, and the latent image is subsequently rendered visible by the application of electroscopic thermoplastic resin particles and colorant. Generally, the electrostatic latent image is developed by using a developer mixture, which usually comprises carrier granules having toner particles adhering triboelectrically thereto, or a liquid developer material, which may include a liquid carrier having toner particles dispersed therein. The developer material is advanced into contact with the electrostatic latent image, and the toner particles are deposited thereon in image configuration. Subsequently, the developed image is transferred to a substrate such as paper. It can be advantageous to transfer the developed image to a coated intermediate transfer web, belt or component, and subsequently transfer with a high transfer efficiency, of for example from about 90 to about 95 percent, the developed image from the intermediate transfer member to a permanent substrate, like paper. The transferred toner image is subsequently usually fixed or fused by heat and pressure upon the substrate.
In electrostatographic printing machines wherein the toner image is electrostatically transferred by a potential difference between the imaging member and the intermediate transfer member, the transfer of the toner particles to the intermediate transfer member, and the retention thereof should be substantially complete so that the image ultimately transferred to the image receiving substrate will have a high resolution. Substantially about 100 percent toner transfer is desired when most or all of the toner particles comprising the image are transferred, and little residual toner remains on the surface from which the image was transferred.
In embodiments, it is desired to provide an intermediate transfer member, which has excellent transfer capabilities; is conductive, and more specifically, has excellent conductivity or resistivity as compared, for example, to an intermediate transfer member where the modified phosphate ester polyimide is absent; and possesses excellent humidity insensitivity characteristics leading to high developed image quality where developed images with minimal resolution issues can be obtained, and where the phosphate ester modified polyimide can be easily removed from substrates either automatically or by simple hand peeling, It is also desired to provide a weldable intermediate transfer belt that may not, but could, have puzzle cut seams, and instead, has a weldable seam, thereby providing a belt that can be manufactured without labor intensive steps, such as manually piecing together the puzzle cut seam with fingers, and without the lengthy high temperature and high humidity conditioning steps. It is also desired to provide an intermediate transfer member, which has excellent wear and abrasion resistance, and more specifically, has excellent mechanical properties as compared, for example, to an intermediate transfer member where a phosphate ester modified polyimide is absent.